1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * include/linux/memory.h - generic memory definition 4 * 5 * This is mainly for topological representation. We define the 6 * basic "struct memory_block" here, which can be embedded in per-arch 7 * definitions or NUMA information. 8 * 9 * Basic handling of the devices is done in drivers/base/memory.c 10 * and system devices are handled in drivers/base/sys.c. 11 * 12 * Memory block are exported via sysfs in the class/memory/devices/ 13 * directory. 14 * 15 */ 16 #ifndef _LINUX_MEMORY_H_ 17 #define _LINUX_MEMORY_H_ 18 19 #include <linux/node.h> 20 #include <linux/compiler.h> 21 #include <linux/mutex.h> 22 #include <linux/notifier.h> 23 24 #define MIN_MEMORY_BLOCK_SIZE (1UL << SECTION_SIZE_BITS) 25 26 struct memory_block { 27 unsigned long start_section_nr; 28 unsigned long state; /* serialized by the dev->lock */ 29 int online_type; /* for passing data to online routine */ 30 int phys_device; /* to which fru does this belong? */ 31 struct device dev; 32 int nid; /* NID for this memory block */ 33 }; 34 35 int arch_get_memory_phys_device(unsigned long start_pfn); 36 unsigned long memory_block_size_bytes(void); 37 int set_memory_block_size_order(unsigned int order); 38 39 /* These states are exposed to userspace as text strings in sysfs */ 40 #define MEM_ONLINE (1<<0) /* exposed to userspace */ 41 #define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */ 42 #define MEM_OFFLINE (1<<2) /* exposed to userspace */ 43 #define MEM_GOING_ONLINE (1<<3) 44 #define MEM_CANCEL_ONLINE (1<<4) 45 #define MEM_CANCEL_OFFLINE (1<<5) 46 47 struct memory_notify { 48 unsigned long start_pfn; 49 unsigned long nr_pages; 50 int status_change_nid_normal; 51 int status_change_nid_high; 52 int status_change_nid; 53 }; 54 55 struct notifier_block; 56 struct mem_section; 57 58 /* 59 * Priorities for the hotplug memory callback routines (stored in decreasing 60 * order in the callback chain) 61 */ 62 #define SLAB_CALLBACK_PRI 1 63 #define IPC_CALLBACK_PRI 10 64 65 #ifndef CONFIG_MEMORY_HOTPLUG_SPARSE 66 static inline void memory_dev_init(void) 67 { 68 return; 69 } 70 static inline int register_memory_notifier(struct notifier_block *nb) 71 { 72 return 0; 73 } 74 static inline void unregister_memory_notifier(struct notifier_block *nb) 75 { 76 } 77 static inline int memory_notify(unsigned long val, void *v) 78 { 79 return 0; 80 } 81 #else 82 extern int register_memory_notifier(struct notifier_block *nb); 83 extern void unregister_memory_notifier(struct notifier_block *nb); 84 int create_memory_block_devices(unsigned long start, unsigned long size); 85 void remove_memory_block_devices(unsigned long start, unsigned long size); 86 extern void memory_dev_init(void); 87 extern int memory_notify(unsigned long val, void *v); 88 extern struct memory_block *find_memory_block(struct mem_section *); 89 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *); 90 extern int walk_memory_blocks(unsigned long start, unsigned long size, 91 void *arg, walk_memory_blocks_func_t func); 92 extern int for_each_memory_block(void *arg, walk_memory_blocks_func_t func); 93 #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT) 94 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 95 96 #ifdef CONFIG_MEMORY_HOTPLUG 97 #define hotplug_memory_notifier(fn, pri) ({ \ 98 static __meminitdata struct notifier_block fn##_mem_nb =\ 99 { .notifier_call = fn, .priority = pri };\ 100 register_memory_notifier(&fn##_mem_nb); \ 101 }) 102 #define register_hotmemory_notifier(nb) register_memory_notifier(nb) 103 #define unregister_hotmemory_notifier(nb) unregister_memory_notifier(nb) 104 #else 105 #define hotplug_memory_notifier(fn, pri) ({ 0; }) 106 /* These aren't inline functions due to a GCC bug. */ 107 #define register_hotmemory_notifier(nb) ({ (void)(nb); 0; }) 108 #define unregister_hotmemory_notifier(nb) ({ (void)(nb); }) 109 #endif 110 111 /* 112 * Kernel text modification mutex, used for code patching. Users of this lock 113 * can sleep. 114 */ 115 extern struct mutex text_mutex; 116 117 #endif /* _LINUX_MEMORY_H_ */ 118